1. Field of the Invention
This invention relates to nondestructive testing and, more particularly, to nondestructive detection of flaws in objects. A flaw may be a crack in an object, a void in an object, and/or a deviation from dimensional specifications of the object, and any other parameter that causes a change in mechanical resonance.
2. The Prior Art
Computational procedures have been developed to find the mechanical resonances of objects other than a sphere but which also have some symmetries. This work is described in "On the modes of free vibrations on inhomogeneous and anisotropic elastic objects" by Visscher et al., J. Acoust Soc. Am., 90 (4) p. 2154, 1991. Examples are, objects, such as a cylinder, rectangular parallel piped, cone, ellipsoid, or pyramids with regular polygon bases.